Different compositions of liposomes on mineralization in rat osteoblast-enriched cultures

• Main Authors: Huang Wei-Chen, 黃薇蓁
• Other Authors: Huang Jiing-Sheng
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/90644187564149187378

碩士 === 高雄醫學大學 === 牙醫學研究所 === 88 === Abstract Destruction of periodontal tissues is characterized by recurrent symptoms such as gingival inflammation, followed by loss of connective tissue and alveolar bone. Many new techniques and materials have been developed in the past years, but there is still no perfect procedure for cementum, alveolar bone and gingival attachment regeneration. Liposomes have been used as the biomembrane model for many years in the research of drug delivery. It has been proven that liposomes have the promotional ability of osteoblast-like cells. As an artificial membranous lipid vesicle, liposomes can serve as the model structure for biological calcification, but there is no definite conclusion that liposomes can function like matrix vesicles to induce bone-like tissue formation and calcification. However, liposomes containing phosphatidylserine(PS)-giving negatively charged liposomes-can be incorporated into the nucleus of osteoblast-like cells, leading to nucleoplasm crystallization and eventual calcification of the entire cell. The experiment included three groups: a control group, a group consisting egg phosphatidylcholine(EPC) and cholesterol (Chol) at different concentrations, and a group containing bovine brain phosphatidylserine (BBPS) with EPC and Chol at different concentrations. Two types of liposomes, each at different concentrations, were added to the 21st-day Sprague-Dawley fetal rat calvarial cell cultures. The purpose of the experiment was to observe the proliferation of osteoblast-like cells by measuring cell numbers and alkaline phosphatase (ALP) activity, and calcified particles stained by von Kossa’s method. The data was analyzed by one-way and two-way ANOVA. The control group and two experimental liposomes showed a significant increase in osteoblastic cell numbers between Day 4-20 and ALP activity between Day 12-16. There was, however, no significant difference in the rate of growth. Calcified particles from Day 12-24 detected by von Kossa’s stain were larger and more abundant in the group containing BBPS, EPC, and Chol than the group consisting only EPC and Chol, or the control group (p＜0.0001). The responses were dependent on the concentration of liposomes. These findings suggest that liposomes can function like matrix vesicles to induce bone-like tissue formation and calcification. However, liposomes will not reduce the expression of osteoblast-like cells or the cell growth in primary rat osteoblast-enriched cultures.